Mixtures which contain carbamate groups and/or allophanate groups and can be cured thermally and by using actinic radiation

ABSTRACT

Mixtures curable thermally and with actinic radiation and containing carbamate and/or allophanate groups, comprising
     (A) at least one of
       (A1) low molecular mass compounds, oligomers and polymers containing allophanate groups, carbamate groups, and carbamate and allophanate groups, and   (A2) low molecular mass compounds, oligomers and polymers containing allophanate groups, carbamate groups, and carbamate and allophanate groups, and additionally allophanate- and/or carbamate-reactive functional groups,    which are substantially or entirely free from reactive functional groups which contain at least one bond which can be activated with actinic radiation, and
 
(C) at least one constituent containing on average per molecule at least one reactive functional group having at least one bond which can be activated with actinic radiation;
 
with the proviso that if only (A1) is used, the mixtures further comprise
   
       (B) at least one of low molecular mass compounds, oligomers and polymers containing allophanate- and/or carbamate-reactive functional groups.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of Patent ApplicationPCT/EP02/06703 filed on 18 Jun. 2002, which claims priority to DE 101 29969.9, filed on 21 Jun. 2001.

The invention relates to novel mixtures containing carbamate and/orallophanate groups, which are curable thermally and with actinicradiation. The present invention additionally relates to processes forpreparing the novel mixtures containing carbamate and/or allophanategroups and curable thermally and with actinic radiation. The presentinvention also relates to the use of the novel mixtures containingcarbamate and/or allophanate groups and curable thermally and withactinic radiation as, or to prepare, coating materials, adhesives andsealing compounds. The present invention relates in particular to theuse of the novel coating materials containing carbamate and/orallophanate groups and curable thermally and with actinic radiation asclearcoat materials, in particular for producing clearcoats as part ofmulticoat color and/or effect paint systems.

Actinic radiation hereinbelow means electromagnetic radiation, such asnear infrared, visible light, UV radiation or X-rays, especially UVradiation, and corpuscular radiation, such as electron beams.

Combined curing by means of heat and actinic radiation is known to thoseskilled in the art as dual cure. Accordingly, the novel mixtures,coating materials, adhesives and sealing compounds under discussion arereferred to as dual-cure mixtures, coating materials, adhesives andsealing compounds.

Thermally curable coating materials comprising constituents containingallophanate groups are known from the German patent application DE 19839 453 A 1. These coating materials are capable of wide application andare outstandingly suitable for the wet-on-wet technique for producingmulticoat color and/or effect paint systems. The paint systems producedfrom the coating materials are highly compatible with other coatingsystems and are scratch-resistant and weathering-stable. The dual-curecrosslinking of these coating materials is not described.

Thermally curable coating materials comprising low molecular masscompounds, oligomers and/or polymers containing carbamate groups areknown from the patent applications EP 0 710 707 A 2, WO 87/00851, EP 0594 068 A 1, EP 0 594 142 A 1, WO 94/10211 and DE 199 46 048 A 1 or fromthe patent EP 0 636 660 B1. The coatings produced from the known coatingmaterials are notable for high etch resistance and chemical resistance.The dual-cure crosslinking of these coating materials is not describedin the literature.

The German patent application DE 199 61 926.3, unpublished at thepriority date of the present specification, describes dual-cure mixtureswhich are curable thermally and with actinic radiation and comprise

-   -   at least one constituent containing on average per molecule at        least one primary or secondary carbamate group and at least one        bond which can be activated with actinic radiation, and    -   at least one constituent containing on average per molecule at        least one carbamate-reactive functional group and also, where        appropriate, at least one bond which can be activated with        actinic radiation.

Besides the customary and known crosslinking agents, the known dual-curemixtures may include reactive diluents which can be cured with actinicradiation, such as difunctional or higher polyfunctional (meth)acrylatessuch as trimethylolpropane tri(meth)acrylate. These additives are to beselected from a long list of suitable additives. The dual-cure mixturesmay be used as coating materials, adhesives and sealing compounds.

The German patent application DE 100 42 152.0, unpublished at thepriority date of the present specification, describes Theological aidswhich can be activated with actinic radiation and possess pseudoplasticproperties. They are prepared by reacting a monoamine, such asbenzylamine, with a polyisocyanate, such as hexamethylene diisocyanate,in the presence of a compound containing at least one functional grouphaving at least one bond which can be activated with actinic radiation,such as dipentaerythritol pentaacrylate. The rheological aids formedfrom urea derivative and dipentaerythritol pentaacrylate are used toprepare dual-cure coating materials.

The dual-cure coating materials may comprise binders containingallophanate and/or carbamate groups and also, where appropriate,functional groups having at least one bond which can be activated withactinic radiation, such as acrylate groups. Moreover, they may compriseamino resin crosslinking agents. Furthermore, they may also includecustomary and known binders curable with actinic radiation alone, suchas (meth)acryloyl-functional (meth)acrylate copolymers, polyetheracrylates, polyester acrylates, unsaturated polyesters, epoxy acrylates,urethane acrylates, amino acrylates, melamine acrylates, siliconeacrylates, and the corresponding methacrylates, and customary and knownreactive diluents curable with actinic radiation, having a functionalityof up to four and being described in Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, “reactivediluents”, pages 491 and 492, such as pentaerythritol tetraacrylate, forexample. The binders, the crosslinking agents, the thermallycrosslinking complementary reactive functional groups, the binderscurable with actinic radiation alone, and the reactive diluents curablewith actinic radiation are to be selected from a plurality of lists, asa result of which numerous possibilities exist for combination. Theexamples and the description reveal that it is primarilyhydroxyl-containing binders and isocyanato-containing crosslinkingagents that are used.

The heat-curable coating materials, adhesives and sealing compoundsknown to date and containing carbamate groups and/or allophanate groups,especially the clearcoat materials, have a number of technicaladvantages, which ought to be retained in the course of their furtherdevelopment. Despite the high technological level attained, thecoatings, adhesive films and seals produced from the existingheat-curable coating materials, adhesives and sealing compoundscontaining carbamate groups and/or allophanate groups still leavesomething to be desired in terms of their scratch resistance and theirreflow characteristics. Moreover, they cannot be additionally cured withactinic radiation.

It is an object of the present invention to provide novel dual-curemixtures curable thermally and with actinic radiation and containingcarbamate and/or allophanate groups, which can be used as dual-curecoating materials, adhesives and sealing compounds and which achieve thehigh technological level of the prior art, if not indeed exceeding it.Furthermore, the novel coating materials, adhesives and sealingcompounds curable thermally and with actinic radiation and containingcarbamate and/or allophanate groups should give coatings, adhesive filmsand seals which attain the high technological level of the prior art, ifnot indeed exceeding it, and at the same time possess high scratchresistance and very good reflow characteristics. They should exhibit agood profile of performance properties, especially as regards scratchresistance and chemical resistance, on and in three-dimensionalsubstrates of complex shape, especially in continuous operation, evenunder conditions of sub-optimum—in particular, incomplete—illuminationof the shadow zones with actinic radiation, thereby allowing theapparatus and measurement and control technology associated with actinicradiation curing to be simplified and the process time to be shortened.

The present invention accordingly provides the novel dual-cure mixturescurable thermally and with actinic radiation and containing carbamateand/or allophanate groups, comprising

-   (A) at least one constituent selected from the group consisting of    -   (A1) low molecular mass compounds, oligomers and polymers        containing allophanate groups, carbamate groups, and carbamate        and allophanate groups, and    -   (A2) low molecular mass compounds, oligomers and polymers        containing allophanate groups, carbamate groups, and carbamate        and allophanate groups, and additionally allophanate- and/or        carbamate-reactive functional groups,-    which are substantially or entirely free from reactive functional    groups which contain at least one bond which can be activated with    actinic radiation,-   (C) at least one constituent containing on average per molecule at    least one reactive functional group having at least one bond which    can be activated with actinic radiation;    with the proviso that the dual-cure mixtures further comprise-   (B) at least one constituent selected from the group consisting of    low molecular mass compounds, oligomers and polymers containing    allophanate- and/or carbamate-reactive functional groups,    if exclusively the constituents (A1) are used.

From the text below, the novel dual-cure mixtures curable thermally andwith actinic radiation and containing carbamate and/or allophanategroups are referred to as “dual-cure mixtures of the invention”.

Further subject matters, processes and uses of the invention will emergefrom the description.

In the light of the prior art it was surprising and unforeseeable forthe skilled worker that the object on which the present invention wasbased could be achieved by means of the dual-cure mixture of theinvention.

A particular surprise was that the coatings, adhesives and seals,especially coatings, produced from the dual-cure mixtures of theinvention combined a high level of hardness with high scratch resistanceand very good reflow characteristics, since hardness and scratchresistance frequently are mutually contradictory parameters.

Not least was it surprising that the dual-cure coating materials,adhesives and sealing compounds of the invention gave coatings, adhesivefilms and seals which possessed a good profile of performance propertiesespecially as regards scratch resistance and chemical resistance, on andin three-dimensional substrates of complex shape, in the shadow zones incontinuous operation, even under conditions of suboptimum, especiallyincomplete, illumination of the shadow zones with actinic radiation,thereby allowing the apparatus and measurement and control technologyassociated with actinic radiation curing to be simplified and theprocess time to be shortened.

Here and below, polymers are understood to be substances containing onaverage per molecule at least 10 monomer units. Oligomers are understoodto be substances containing on average per molecule from 3 to 15 monomerunits. For further details of these terms, refer to Römpp Lexikon Lackeund Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998,“oligomers”, page 425.

The dual-cure mixtures of the invention comprise at least one lowmolecular mass compound, oligomer and/or polymer (A) selected from thegroup consisting of low molecular mass compounds, oligomers and polymerswhich contain allophanate groups, carbamate groups, or allophanategroups and carbamate groups and which are substantially or entirely freefrom reactive functional groups containing at least one bond which canbe activated with actinic radiation.

“Substantially free from reactive functional groups” means that theconstituents (A) may contain a small amount of such reactive functionalgroups, originating for example from the preparation method of thecomponents (A), the amount in question being, however, insignificant asfar as crosslinking is concerned.

Preference is given to using the oligomers and/or polymers (A), whichare also referred to as binders.

The allophanate oligomers and/or polymers (A) contain on average permolecule at least one allophanate group and preferably at least two,with particular preference at least three, and in particular at leastfour, allophanate groups.

The allophanate and carbamate oligomers and/or polymers (A) contain onaverage per molecule at least one allophanate group and at least onecarbamate group and also preferably at least two, with particularpreference at least three, and in particular at least four, allophanategroups and at least one carbamate group, in particular at least twocarbamate groups.

The carbamate oligomers and/or polymers (A) contain on average permolecule preferably at least one carbamate group and more preferably atleast two, with particular preference at least three, and in particularat least four, carbamate groups.

The amount of the constituents (A) in the dual-cure mixtures of theinvention may vary very widely and is guided by the requirements of therespective intended use. Preferably, the dual-cure mixtures of theinvention contain the constituents (A) in an amount, based in each caseon the solids of the dual-cure mixture of the invention, of from 10 to90%, more preferably from 12 to 85%, with particular preference from 14to 80%, with very particular preference from 16 to 75%, and inparticular from 18 to 75% by weight.

Hereinbelow, solids means the sum of those constituents of therespective dual-cure mixture of the invention which, following the heatcure, constitute the coatings, adhesive films or seals.

The dual-cure mixtures of the invention further comprise at least oneconstituent (B) selected from the group consisting of low molecular masscompounds, oligomers and polymers containing allophanate- and/orcarbamate-reactive functional groups. Preference is given to using thelow molecular mass compounds (B), which are also referred to ascrosslinking agents. The crosslinking agents (B) are employed when theconstituents (A) contain no carbamate- and/or allophanate-reactivefunctional groups, i.e., are not self-crosslinking.

The amount of the crosslinking agents (B) in the dual-cure mixtures ofthe invention may likewise vary widely. The amount is preferably from 5to 40%, more preferably from 6 to 35%, with particular preference from 7to 30%, with very particular preference from 8 to 25%, and in particularfrom 9 to 20% by weight, based in each case on the solids of thedual-cure mixture of the invention. In this context it is furtheradvisable to choose the amounts of crosslinking agent (B) and lowmolecular mass compounds, oligomers and/or polymers (A1) in such a waythat in the dual-cure mixtures of the invention the ratio ofcomplementary reactive functional groups in the crosslinking agent (B)to reactive functional groups in the constituents (A1) is from 2:1 to1:2, preferably from 1.5:1 to 1:1.5, with particular preference from1.2:1 to 1:1.2, and in particular from 1.1:1 to 1:1.1. Similar commentsapply to the self-crosslinking binders (A2) and to the mixtures ofbinders (A1) and (A2) and crosslinking agents (B).

Furthermore, the dual-cure mixtures of the invention comprise at leastone constituent (C) which contains on average per molecule at least onereactive functional group having at least one bond which can beactivated with actinic radiation. Furthermore, the constituent (C ) mayalso include at least one allophanate- and/or carbamate-reactivefunctional group.

The amount of the constituents (C) in the dual-cure mixtures of theinvention may likewise vary widely. Preferably the amount is from 5 to50%, more preferably from 6 to 45%, with particular preference from 7 to40%, with very particular preference from 8 to 35%, and in particularfrom 9 to 30% by weight, based in each case on the solids of thedual-cure mixture of the invention.

Over and above this, the dual-cure mixtures of the invention may alsocomprise at least one rheological aid (D) having pseudoplasticproperties. The Theological aid (D) is preferably selected from thegroup consisting of urea derivatives and silicas.

The amount of the Theological aids (D) in the dual-cure mixtures of theinvention may vary very widely. The dual-cure mixtures of the inventionpreferably contain the rheological aids (D) in an amount, based in eachcase on the solids of the dual-cure mixture of the invention, of from0.1 to 10%, more preferably from 0.2 to 9%, with particular preferencefrom 0.3 to 8%, with very particular preference from 0.4 to 7%, and inparticular from 0.5 to 6% by weight.

The dual-cure mixtures of the invention may further comprise at leastone wetting agent (E).

Where used, the wetting agents (E) are present in the dual-cure mixturesof the invention in an amount, based in each case on the solids of thedual-cure mixture of the invention, of preferably from 0.01 to 5%, morepreferably from 0.02 to 4%, with particular preference from 0.03 to 3%,with very particular preference from 0.04 to 2%, and in particular from0.05 to 1% by weight.

Additionally, the dual-cure mixtures of the invention may furthercomprise customary and known pigments (F) and/or additives (G).

Examples of suitable low molecular mass compounds (A) are described indetail in the literature

-   -   EP 0 710 707 A 2, page 4 lines 1 to 27, or EP 0 915 113 A 1,        page 2 lines 44 to 48 and page 6 lines 21 to 25,    -   EP 0 636 660 B 1, column 1 line 41 to column 2 line 3, column 2        line 12 to column 3 line 32, and column 5 line 43 to column 6        line 36, or WO 87/00851, page 13 line 11 to page 15 line 8 and        example 1 to example 33, pages 17 to 27.

These low molecular mass compounds (A) permit the preparation ofparticularly high-solids compositions of the invention.

Suitable binders (A) come from the polymer classes of the random,alternating and/or block, linear and/or branched and/or comb, addition(co)polymers of ethylenically unsaturated monomers, or polyadditionresins and/or polycondensation resins. For further details on theseterms, refer to Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, New York, 1998, page 457, “polyaddition” and“polyaddition resins (polyadducts)”, and also pages 463 and 464,“polycondensates”, “polycondensation” and “polycondensation resins”.

Examples of highly suitable addition (co)polymers (A) are (meth)acrylatecopolymers and particularly saponified polyvinyl esters, especially(meth)acrylate copolymers.

Examples of highly suitable polyaddition resins and/or polycondensationresins (A) are polyesters, alkyds, polyurethanes, polylactones,polycarbonates, polyethers, epoxy resin-amine adducts, polyureas,polyamides or polyimides, especially polyesters.

With very particular preference, the oligomers and/or polymers (A) comefrom the polymer classes of the (meth)acrylate copolymers andpolyesters.

Oligomers and polymers (A) that contain allophanate groups and come fromthe abovementioned polymer classes are known from the German patentapplication DE 198 39 453 A 1, page 2 line 65 to page 6 line 34 and page7 lines 25 to 53.

Oligomers and polymers (A) that contain carbamate groups and come fromthe abovementioned polymer classes, and processes for preparing them,are known from the patent applications

-   -   EP 0 594 068 A 1, page 2 line 45 to page 4 line 27, page 5 lines        36 to 57 and page 7 lines 1 to 22,    -   EP 0 594 142 A 1, page 3 line 1 to page 4 line 37, page 5 line        49 to page 6 line 12 and page 7 lines 5 to 26,    -   WO 94/10211, page 4 line 18 to page 8 line 8, page 12 line 30 to        page 14 line 36, page 15 line 35 to page 17 line 32 and page 18        line 16 to page 19 line 30, and    -   DE 199 46 048 A 1.

The oligomers and/or polymers (A) are preferably prepared bycopolymerizing a monomer mixture containing at least one olefinicallyunsaturated carboxylic acid, methacrylic acid for example, in thepresence of a glycidyl ester of Versatic® acid (see Römpp Lexikon Lackeund Druckfarben, Georg Thieme Verlag, Stuttgart New York, 1998“Versatic® acids”, pages 605 and 606) and then reacting the resultanthydroxyl-containing (meth)acrylate copolymer with at least one alkylcarbamate, such as methyl, propyl or butyl carbamate. Or elsehydroxyl-containing (meth)acrylate copolymers are converted usingphosgene into (meth)acrylate copolymers containing chloroformate groups,after which the chloroformate groups are converted into carbamate groupsusing ammonia or primary amines. It is also possible to reactisocyanato-containing (meth)acrylate copolymers or polyesters with atleast one hydroxylalkyl carbamate, such as 2-hydroxyethyl carbamate.

The oligomers and polymers (A) preferably have a number-averagemolecular weight of from 600 to 20,000, more preferably from 800 to15,000, with particular preference from 1,000 to 10,000, with veryparticular preference from 1,200 to 8,000, and in particular from 1,200to 6,000 daltons.

Besides the allophanate and/or carbamate groups, the constituents (A),especially the oligomers and/or polymers (A), may also contain at leastone functional group selected from the group consisting of

-   -   (i) allophanate- and carbamate-reactive functional groups,    -   (ii) dispersing groups by means of which the oligomers and/or        polymers (A) are rendered soluble or dispersible in water.

Examples of suitable allophanate- and/or carbamate-reactive functionalgroups (i) are N-methylol groups and N-methylol ether groups, preferablythe methyl, ethyl, n-propyl and/or n-butyl ethers. The constituents (A2)in question, especially the oligomers and/or polymers (A2), are in thatcase partially or fully self-crosslinking, and so in this case it ispossible substantially or entirely to forgo the use of crosslinkingagents (B).

Examples of suitable dispersing groups (ii) are anion-forming groups,such as carboxylic acid, sulfonic acid or phosphonic acid groups, oranionic groups, such as carboxylate, sulfonate or phosphonate groups,cation-forming groups, such as primary, secondary or tertiary aminogroups, or cationic groups, examples being ammonium groups, such asprimary, secondary, tertiary or quaternary ammonium groups, sulfoniumgroups and phosphonium groups, or polyalkylene oxide groups, such aspolyethylene oxide groups, which may be incorporated laterally,terminally and/or chain-internally into the oligomers and polymers (A)(cf. Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,Stuttgart, New York, 1998, “water-dispersible binders” page 619, and“water-soluble binders”, pages 626 and 625).

The preparation of the oligomers and/or polymers (A) containing theabove-described groups (i) and/or (ii) also has no special features interms of its method but instead takes place with the aid of the methodsand the apparatus which are known from the patent applications citedabove or are described in the German patent application DE 199 61 926.3,unpublished at the priority date of the present specification.

Accordingly, for example, groups (i) may be introduced by thecopolymerization of olefinically unsaturated monomers containingN-methylol ether groups or by polymer-analogous reactions of lateraland/or terminal amino groups with formaldehyde.

Groups (ii) may be incorporated, for example, by copolymerization ofolefinically unsaturated carboxylic acids, such as acrylic acid ormethacrylic acid or via the polymer-analogous reaction of hydroxylgroups with carboxylic anhydrides, such as maleic anhydride or phthalicanhydride.

Suitable crosslinking agents (B) are amino resins.

Suitable amino resins include in principle all formaldehyde-containingresins such as are commonly used as crosslinking agents in the field ofcoating materials, adhesives and sealing compounds. Preference is givento using melamine resins.

Examples of suitable amino resins are described in Römpp Lexikon Lackeund Druckfarben, Georg Thieme Verlag, 1998, page 29, “amino resins”, inthe textbook “Lackadditive” [Additives for coatings] by Johan Bieleman,Wiley-VCH, Weinheim, N.Y., 1998, pages 242 ff., in the book “Paints,Coatings and Solvents”, second, completely revised edition, edited by D.Stoye and W. Freitag, Wiley-VCH, Weinheim, N.Y., 1998, pages 80 ff., inthe American patent U.S. Pat. No. 4,710,542 A or in the patentapplications EP 0 245 700 A 1 and WO 00/37520, page 3 lines 1 to 13, andalso in the article by B. Singh and coworkers, “CarbamylmethylatedMelamines, Novel Crosslinkers for the Coatings Industry”, in AdvancedOrganic Coatings Science and Technology Series, 1991, Volume 13, pages193 to 207.

The constituents (C) curable with actinic radiation contain on averageper molecule at least one reactive functional group, preferably at leasttwo, with particular preference at least three, and in particular three,reactive functional groups which contain(s) at least one, especiallyone, bond which can be activated with actinic radiation.

Furthermore, the constituents (C) may contain at least one of theabove-described allophanate- and/or carbamate-reactive functionalgroups.

Examples of suitable bonds which can be activated with actinic radiationare carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen,carbon-nitrogen, carbon-phosphorus or carbon-silicon single bonds ordouble bonds. Of these, the double bonds, especially the carbon-carbondouble bonds (referred to as “double bonds” below), are employed withpreference.

Highly suitable double bonds are present, for example, in(meth)acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinylester, ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl,isopropenyl, allyl or butenyl groups; ethenylarylene ether,dicyclopentadienyl ether, norbornenyl ether, isoprenyl ether,isopropenyl ether, allyl ether or butenyl ether groups; orethenylarylene ester, dicyclopentadienyl ester, norbornenyl ester,isoprenyl ester, isopropenyl ester, allyl ester or butenyl ester groups.Of these, (meth)acrylate groups, especially acrylate groups, are ofparticular advantage and are therefore used with very particularpreference in accordance with the invention.

The parent structure to which the double bonds are attached is notcritical; rather, it is possible to make use, for example, of polymersand/or oligomers which come from the polymer classes described above inconnection with the binders (A). The double bonds may be incorporated inthe customary and known manner by way of polymer-analogous reactions oflateral and/or terminal hydroxyl groups with olefinically unsaturatedmonoisocyanates, such as vinyl isocyanate, methacryloyl isocyanate or1-(1-isocyanato-1-methylethyl)-3-(1-methylethenyl) benzene (TMI® fromCYTEC), of lateral and/or terminal isocyanate groups withhydroxyl-containing, olefinically unsaturated monomers such ashydroxyethyl, acrylate, or of lateral and/or terminal epoxide groupswith olefinically unsaturated carboxylic acids, such as acrylic acid ormethacrylic acid.

Examples of suitable constituents (C), containing up to four doublebonds, are described in Römpp Lexikon Lacke und Druckfarben, GeorgThieme Verlag, Stuttgart, New York, 1998, “reactive diluents”, pages 491and 492, or in the German patent application DE 198 18 735 A 1, column 7lines 1 to 25.

Examples of suitable constituents (C) containing six or more doublebonds in the molecule are (meth)acryloyl-functional (meth)acryliccopolymers, polyether acrylates, polyester acrylates, unsaturatedpolyesters, epoxy acrylates, urethane acrylates, amino acrylates,acrylated amino resins, such as melamine acrylates, silicone acrylatesand the corresponding methacrylates. Of these, the urethane(meth)acrylates (C) are advantageous and are therefore used withparticular preference.

The urethane (meth)acrylates (C) and processes for preparing them areknown, for example, from the patent applications and patents EP 0 204161 A 1, DE 196 45 761 A 1, WO 98/10028, EP 0 742 239 A 1, EP 0 661 321B 1, EP 0 608 021 B 1, EP 0 447 998 B 1, or EP 0 462 287 B 1. Theurethane (meth)acrylates (C) are commercially customary products and aresold, for example, under the brand name Ebecryl® 1290 by UCB, Belgium,or under the brand name Rahn® 99–664 by Rahn.

Further examples of suitable constituents (C) are known from the Germanpatent application DE 198 18 735 A 1, column 2 lines 24 to 36, column 3line 16 to column 6 line 33 and column 6 lines 34 to 68. Highly suitableexamples are pentaerythritol triacrylate, which is sold under the brandname Sartomer® 444 D by Cray Valley, France, and dipentaerythritolpentaacrylate, which is sold by the same company under the brand nameSartomer® 399.

The rheological aids (D) are selected from the group consisting of ureaderivatives and silicas.

Suitable Theological aids (D) are known, for example, from theliterature EP 0 192 304 A 1, DE 23 59 923 A 1, DE 18 05 693 A 1, WO94/22968, DE 27 51 761 C 2, WO 97/12945 and “farbe+lack”, 11/1992, pages829 ff., WO 00/31194, WO 00/37520, DE 199 24 172 A 1, DE 199 24 171 A 1or DE 199 24 170 A 1.

It is preferred to use rheological aids (D) which are preparable byreacting at least one amine and/or water with at least one isocyanate inthe presence of at least one amino resin and/or at least one of theabove-described oligomers and/or polymers (A). They are preferablyprepared using the amines.

The amines preferably selected from the group consisting of acyclicaliphatic, aliphatic-aromatic, cycloaliphatic, aliphatic-cycloaliphaticand cycloaliphatic-aromatic primary and secondary monoamines andpolyamines.

Examples of suitable monoamines are known from the German patentapplications DE 199 24 172 A 1, page 3 lines 3 to 10, and DE 199 24 171A 1, page 3 lines 35 to 42, or from the international patentapplications WO 00/31194, page 11 lines 14 to 29, and WO 00/37520, page3 line 15 to page 4 line 5. Particular preference is given to usingmethoxypropylamine, benzylamine and/or n-hexylamine.

The polyamines contain on average per molecule at least two primaryand/or secondary amino groups. Examples of suitable polyamines are knownfrom the international patent application WO 00/37520, page 4 lines 6 to19.

Suitable isocyanates include monoisocyanates and polyisocyanates. Themonoisocyanates are used for the reaction with polyamines and thepolyisocyanates for the reaction with the monoamines. Preferably thepolyisocyanates and the monoamines are used to prepare the Theologicalaids (D).

Examples of suitable monoisocyanates are known from the internationalpatent application WO 00/37520, page 4 line 21 to page 5 line 2.

Preference is given to using polyisocyanates containing on average permolecule at least 1.8, more preferably at least 2, and in particular 2,isocyanate groups. Examples of suitable polyisocyanates anddiisocyanates are described in detail in the international patentapplications WO 00/31194, page 11 line 30 to page 12 line 26, and WO00/37520, page 5 line 4 to page 6 line 27, or from the German patentapplications DE 199 24 172 A 1, page 3 lines 11 to 23, DE 199 24 170 A1, column 3 line 61 to column 6 line 68, and DE 199 24 171 A 1, page 3line 43 to page 5 line 34. Particular preference is given to usinghexamethylene diisocyanate and its oligomers, especially trimers.

Suitable amino resins include in principle all formaldehyde-containingresins such as are commonly used as crosslinking agents (B) in the fieldof coating materials, adhesives and sealing compounds. It is preferredto use melamine resins. The amount of amino resins introduced into thedual-cure mixtures of the invention by the rheological aids (D) isincluded in the amount of crosslinking agents (B) in said mixtures.

Suitable oligomers and polymers (A) are those described above. Theamount of constituents (A) introduced into the dual-cure mixtures of theinvention by the Theological aids (D) is included in the amount ofbinders (A) in said mixtures.

The reaction of the amines or of water, especially of the amines, withthe isocyanates in the presence of the amino resins has no specialfeatures in terms of its method but instead takes place as described inthe international patent application WO 00/37520, page 6 line 29 to page8 line 14 and page 9 line 28 to page 10 line 32.

The reaction of the amines or of water, especially of the amines, withthe isocyanates in the presence of the oligomers and/or polymers (A)likewise has no special features in terms of its method but insteadtakes place as described in the international patent application WO00/31194, page 12 line 23 to page 13 line 19.

For the preparation of the urea derivatives (D) on the tonne scale, thecontinuous process known from the German patent application DE 199 03283 A 1, in which an inline dissolver is used as the mixing unit, isadvantageous. In this case the weight ratio of amino resin and/oroligomer and/or polymer (A) to rheological aid (D) may be 100:1,preferably 90:1, more preferably 80:1, with particular preference 70:1,with very particular preference 60:1, and in particular 50:1.

Amino resins (B) comprising Theological aids (D) prepared in this wayare customary and known and are sold, for example, under the brand nameSetamine® XL 1268 by Akzo Nobel.

The silicas used as Theological aids (D) are selected from the groupconsisting of modified pyrogenic, hydrophilic and hydrophobic,transparent silicas. Particular preference is given to using hydrophobicpyrogenic silicon dioxides whose agglomerates and aggregates have achainlike structure and which may be prepared by flame hydrolysis ofsilicon tetrachloride in an oxyhydrogen flame. Preferably, they have aprimary particle size of from 2 to 20 nm. They are sold, for example, byDegussa under the brand name Aerosil®. Particular preference is alsogiven to using precipitated waterglasses, such as nanohectorites, whichare sold, for example, by Südchemie under the brand name Optigel® or byLaporte under the brand name Laponite®. Further examples of suitablesilicas are those known from the German patent application DE 199 24 172A 1, page 3 lines 28 to 32. Yet another example of suitable hydrophilic,transparent silicas is Aerosil® 380 with an internal surface area of 380m²/g (measured by the BET method in accordance with DIN 66131).

Preference is given to using wetting agents (E) as defined in RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York,1998 “wetting agents”, page 409.

It is preferred to use wetting agents (E) selected from the groupconsisting of siloxanes, fluorine compounds, carboxylic monoesters,phosphates, polyacrylic acids and their copolymers, and polyurethanes.Preferably, polyurethanes are used.

Further suitable wetting agents (E) are described in Johan Bieleman,“Lackadditive”, Wiley-VCH, Weinheim, N.Y., 1998, “4 Surface-activecompounds”, pages 69 to 100, especially “4.1.4 Chemical composition ofwetting agents and dispersants”, pages 87 to 92, and “4.1.8 Commercialproducts”, page 100, or in the German patent application DE 199 24 171 A1, page 2 line 63 to page 3 line 24.

Examples of highly suitable wetting agents (E) are the commercialproducts

-   -   Texaphor® 963 from Cognis (low molecular mass electroneutral        salt of a polycarboxylic acid with amine derivatives, 50 percent        in higher aromatics),    -   Texaphor® 3112 from Cognis (high molecular mass polyurethane, 50        percent in xylene/butyl acetate 2:3),    -   Disperbyk® 110 from Byk Chemie (anionic copolymer containing        acidic groups, acid number: 53 mg KOH/g, 50 percent in        methoxypropyl acetate/alkylbenzene 1:1),    -   Disperbyk® 161 from Byk Chemie (high molecular mass        polyurethane, amine number: 11 mg KOH/g, 30 percent in        methoxypropyl acetate/butyl acetate 6:1),    -   Disperbyk® 166 from Byk Chemie (high molecular mass        polyurethane, amine number: 20 mg KOH/g, 30 percent in butyl        acetate/methoxypropyl acetate 4:1),    -   Efka® 4163 from Efka (high molecular mass polyurethane, amine        number: 11 mg KOH/g, 30 percent in methoxypropyl acetate/butyl        acetate 6:1), and    -   Efka® 4047 from Efka (high molecular mass polyurethane, amine        number: 10 to 20 mg KOH/g, 35 percent in butyl        acetate/methoxypropyl acetate/secondary butanol).

The dual-cure mixtures of the invention further comprise at least onepigment (F).

The pigments (F) are preferably selected from the group consisting ofcustomary and known, organic and inorganic, color and/or effectpigments, electrically conductive pigments, magnetically shieldingpigments, and fluorescent pigments, and customary and known, organic andinorganic fillers and nanoparticles, other than the Theological aids(D).

These pigments (F) are used particularly when the dual-cure mixtures ofthe invention are intended for use as pigmented adhesives or sealingcompounds and also coating materials, such as primer-surfacers, basecoatmaterials or solid-color topcoat materials.

Furthermore, the dual-cure mixtures of the invention may compriseadditives (G), which may be used both in the pigmented and in theunpigmented dual-cure mixtures of the invention. Examples of suitableadditives (G) are known from the German patent applications DE 199 24170 A 1, column 13 line 6 to column 14 line 2, DE 199 24 171 A 1, page 8line 65 to page 9 line 33, and DE 198 39 453 A 1, page 6 line 68 to page7 line 6, with the exception of the wetting agents (E) and thetransparent fillers based on silicon dioxide.

As additives (G) it is also possible to use compounds containingcarbamate groups or carbamate-reactive functional groups and alsoreactive functional groups having at least one bond which can beactivated with actinic radiation, as described in the German patentapplications DE 199 61 926.3 and DE 100 41 634.9, both unpublished atthe priority date of the present specification.

Not least, the dual-cure mixtures of the invention may comprisephotoinitiator additives (G). Suitable photoinitiators (G) are those ofthe Norrish II type, whose mechanism of action is based on anintramolecular variant of the hydrogen abstraction reactions such asoccur diversely in the case of photochemical reactions (by way ofexample, refer here to Römpp Chemie Lexikon, 9th, expanded and revisededition, Georg Thieme Verlag Stuttgart, Vol. 4, 1991) or other examplesof cationic photoinitiators (by way of example, refer here to RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag Stuttgart, 1998,pages 444 to 446), especially benzophenones, benzoins or benzoin ethers,or phosphine oxides. It is also possible to Make use, for example, ofthe products available commercially under the names Irgacure® 184,Irgacure® 1800 and Irgacure® 500 from Ciba Geigy, Genocure® MBF fromRahn and Lucirin® TPO from BASF AG.

The preparation of the dual-cure mixtures of the invention has nospecial features in terms of its method but instead takes place by themixing of the above-described constituents. This may be done usingmixing units such as stirred tanks, dissolvers, inline dissolvers,stirred mills, static mixers, toothed-ring dispersers or extruders. Itis preferred to operate here in the absence of actinic radiation, inorder to prevent damage to the dual-cure mixtures of the invention,especially as a result of premature crosslinking.

Depending on the intended use, the mixtures of the invention may bepresent in organic solvents as solutions and/or dispersions (nonaqueousdispersions, NADs) or as substantially or entirely solvent-freemixtures. The substantially or entirely solvent-free mixtures may bepresent in liquid forms (100% systems) or in powder form. Furthermore,the mixtures of the invention may be present as dispersions or solutionsin water. Not least, the pulverulent mixtures of the invention may be inthe form of what are known as powder slurries, in dispersions in water.Preferably, the mixtures of the invention are present as dispersionsand/or solutions in organic solvents.

The dual-cure mixtures of the invention are outstandingly suitable as,or to prepare, dual-cure coating materials, adhesives and sealingcompounds. The dual-cure coating materials of the invention areoutstandingly suitable for the production of single-coat or multicoat,color and/or effect, electrically conductive, magnetically shielding orfluorescent coatings, such as primer-surfacer coats, basecoats orsolid-color topcoats, or of single-coat or multicoat clearcoat systems.The dual-cure adhesives of the invention are outstandingly suitable forthe production of adhesive films, and the dual-cure sealing compounds ofthe invention are outstandingly suitable for the production of seals.

Very particular advantages result when the dual-cure mixtures of theinvention are used as dual-cure clearcoat materials to producesingle-coat or multicoat clearcoat systems. In particular, the dual-cureclearcoat materials of the invention are used to produce multicoat colorand/or effect paint systems in accordance with the wet-on-wet technique,in which a basecoat material, especially an aqueous basecoat material,is applied to the surface of a substrate and then the resultant basecoatfilm is dried, without being cured, and is overcoated with a clearcoatfilm. The two films are then cured together.

In terms of its method, the application of the dual-cure coatingmaterials, adhesives and sealing compounds of the invention has nospecial features but may instead take place by any customary applicationmethod, such as spraying, knife coating, brushing, flow coating,dipping, trickling or rolling, for example. In the context of thecoating materials of the invention it is preferred to employ sprayapplication methods, unless the materials in question are powder coatingmaterials, which are preferably applied by means of the fluidized bedtechniques as known, for example, from the BASF Coatings AG companydocuments “Pulverlacke für Industrielle Anwendungen” [Powder coatingmaterials for industrial applications], January 2000, or “CoatingsPartner, Pulverlack Spezial” [Powder coatings special], 1/2000, or RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York,1998, pages 187 and 188, “Electrostatic powder spraying”, “Electrostaticspraying” and “Electrostatic fluidized bath process”.

Here too it is advisable to operate in the absence of actinic radiationin order to prevent premature crosslinking of the dual-cure coatingmaterials, adhesives and sealing compounds of the invention.

Suitable substrates are all those whose surface is not damaged by theapplication of heat and actinic radiation in the course of the curing ofthe films present thereon. The substrates preferably consist of metals,plastics, wood, ceramic, stone, textile, fiber composites, leather,glass, glass fibers, glass wool and rock wool, mineral- and resin-boundbuilding materials, such as plaster board and cement slabs or rooftiles, and also composites of these materials.

Accordingly, the coating materials, adhesives and sealing compounds ofthe invention are suitable for the coating, bonding and sealing of motorvehicle bodies or parts thereof, of the interior and exterior of motorvehicles, of buildings inside and out, of furniture, windows and doors,and, in the context of industrial coating, for the coating, bonding andsealing of small parts, such as nuts and bolts, hubcaps or wheel rims,of coils, containers, packaging, electrical components, such as motorwindings or transformer windings, and of white goods, such as domesticappliances, boilers and radiators.

In the case of electrically conductive substrates it is possible to useprimers which are produced in a customary and known manner fromelectrocoat materials. For this purpose both anodic and cathodicelectrocoat materials are suitable, but especially the cathodic ones.Unfunctionalized and/or nonpolar plastics surfaces may be subjectedprior to coating in a known manner to a pretreatment, such as with aplasma or by flaming, or may be provided with a water-based primer.

The curing of the applied dual-cure mixture of the invention also has nospecial features in terms of its method but instead takes place inaccordance with the customary and known thermal methods, such as heatingin a forced air oven or exposure to IR lamps. For curing with actinicradiation, suitable radiation sources are those such as high-pressure orlow-pressure mercury vapor lamps, with or without lead doping in orderto open up a radiation window of up to 405 nm, or electron beam sources.Further examples of suitable methods and apparatus for curing withactinic radiation are described in the German patent application DE 19818 735 A 1, column 10 lines 31 to 61.

The resultant coatings of the invention, especially the single-coat ormulticoat color and/or effect paint systems and clearcoats of theinvention, are easy to produce and exhibit outstanding opticalproperties and very high light stability, chemical resistance, waterresistance, condensation resistance, and weathering stability. Inparticular, they are free from turbidities and inhomogeneities. Theyexhibit very good reflow characteristics, outstanding intercoat adhesionbetween basecoat and clearcoat, and good to very good adhesion tocustomary and known automotive refinishes.

The adhesive films of the invention durably and thermally join a verywide variety of substrates to one another and possess high chemical andmechanical stability even in the case of extreme temperatures and/ortemperature fluctuations.

Similarly, the seals of the invention seal the substrates durably, andexhibit high chemical and mechanical stability even in the case ofextreme temperatures and/or temperature fluctuations and even inconjunction with exposure to aggressive chemicals.

In particular, however, the coatings of the invention possess highhardness and scratch resistance, and so may be used with particularadvantage in the field of automotive coatings.

A further advantage of the novel dual-cure coating materials, adhesivesand sealing compounds is that, even in the shadow zones ofthree-dimensional substrates of complex shape, such as vehicle bodies,radiators or electrical wound goods, and even without optimum—inparticular, complete—illumination of the shadow zones with actinicradiation, they give coatings, adhesive films and seals whose profile ofperformance properties is at least equal to that of the coatings,adhesive films and seals outside of the shadow zones. As a result, thecoatings, adhesive films and seals located in the shadow zones are nolonger easily damaged by mechanical and/or chemical attack, such as mayoccur, for example, when further components of motor vehicles areinstalled into the coated bodies.

Accordingly, the primed or unprimed substrates commonly employed in thetechnological fields recited above and coated with at least one coatingof the invention, bonded with at least one adhesive film of theinvention and/or sealed with at least one seal of the invention combinea particularly advantageous profile of performance properties with aparticularly long service life, so making them particularly attractiveeconomically.

EXAMPLES Preparation Example 1

The Preparation of a Hydroxyl-Containing Methacrylate Copolymer

A 4-liter reactor equipped with a stirrer, two dropping funnels as feedsfor the monomer mixture and the initiator solution, a nitrogen inletpipe, a thermometer and a reflux condenser was charged with 731 parts byweight of an aromatic hydrocarbon fraction having a boiling range offrom 158 to 172° C. and this initial charge was heated to 140° C.Thereafter a monomer mixture of 183 parts by weight of n-butylmethacrylate, 458 parts by weight of ethylhexyl methacrylate, 214 partsby weight of styrene, 183 parts by weight of hydroxyethyl acrylate, 458parts by weight of 4-hydroxybutyl acrylate and 31 parts by weight ofacrylic acid was metered into the reactor at a uniform rate over thecourse of 4 hours and an initiator solution of 153 parts by weight oftert-butyl perethylhexanoate in 92 parts by weight of theabove-described aromatic solvent was metered into the reactor at auniform rate over the course of 4.5 hours. The addition of the monomermixture and of the initiator solution was commenced simultaneously.After the end of the addition of the initiator, the reaction mixture washeated at 140° C. with stirring for two hours more and then cooled. Theresulting resin solution had a solids content of 65% (forced air often;one hour; 130° C.).

Preparation Example 2

The Preparation of a Chloroformate-Functional Methacrylate Copolymer

700 parts by weight of the resin solution from preparation example 1were diluted with 700 parts by weight of xylene in order to improvestirrability. The resulting mixture was introduced into an appropriatereactor. Subsequently, over the course of one hour, 400 parts by weightof phosgene were added to the resin solution at room temperature andwith stirring. After a subsequent reaction period of 30 minutes, thedegree of conversion was determined by means of IR spectroscopy. Whenthis was done, hydroxyl groups were no longer detectable. The excessphosgene was separated off under reduced pressure. From thedetermination of the chlorine value, a conversion >90% was found.

Preparation Example 3

The Preparation of the Carbamate-Functional Methacrylate Copolymer (A)

1 450 parts by weight of the chloroformate-functional resin solutionfrom preparation example 2 were introduced into an appropriate reactor.Subsequently, 61 parts by weight of ammonia were introduced into theresin solution at room temperature, with ammonium chloride beingprecipitated.

The resulting resin solution was admixed in succession with 500 parts byweight of water, 400 parts by weight of ethanol and 500 parts by weightof pentyl acetate in order to dissolve the precipitated ammoniumchloride and to bring about phase separation. The resulting mixture wasstirred at room temperature for one hour and then left to stand in orderfor phase separation to take place. After it had taken place, theaqueous phase was separated off and the organic phase was dried oversodium chloride.

NMR analysis revealed that more than 80% of the chloroformate groups hadbeen converted into carbamate groups. The resulting solution of thepolyacrylate resin of the invention had a solids content of 68.6% byweight (forced air oven; one hour; 130° C.), a viscosity of 8.4 dPas(original) and a viscosity of 5.6 dPas in 65% dilution in solventnaphtha.

Example 1

The Preparation of an Inventive Clearcoat Material

The inventive clearcoat material was prepared by mixing and homogenizingthe following constituents:

-   -   222 parts by weight of the methacrylate copolymer solution (A)        from preparation example 3,    -   42.2 parts by weight of Setamine® XL 1268 [urea-modified        melamine resin (Resimene® 755 from Monsanto, 80 percent in        isobutanol) from Akzo Nobel; amount of Theological aid (B)        present: 2.4% by weight],    -   30 parts by weight of pentaerythritol triacrylate (Sartomer®        444D),    -   5.2 parts by weight of Tinuvin® 400 (commercial UV absorber from        Ciba Specialty Chemicals, Inc.),    -   2.6 parts by weight of Tinuvin® 123 (commercial reversible        free-radical scavenger, sterically hindered amine (HALS) from        Ciba Specialty Chemicals, Inc.),    -   6.8 parts by weight of Nacure® 5528 (commercial catalyst        (amine-blocked sulfonic acid derivative) from King),    -   6.0 parts by weight of a five percent strength solution of a        commercial leveling agent based on polydimethylsiloxane in        xylene,    -   0.8 part by weight of Byk® 306 (commercial additive from Byk        Chemie),    -   4.0 parts by weight of Irgacure® 184 (commercial photoinitiator        from Ciba Specialty Chemicals, Inc.),    -   1.0 part by weight of Lucirin® TPO (commercial photoinitiator        from BASF Aktiengesellschaft),    -   31 parts by weight of ethylhexanol,    -   15 parts by weight of n-butanol,    -   3 parts by weight of pine oil, 85 percent, and    -   20 parts by weight of butyl diglycol.

Using the mixture of the abovementioned solvents, the dual-cureclearcoat material was adjusted to a viscosity of 30 seconds in the DIN4 flow cup. It then had a solids content of 55.3% by weight (one hour,forced air oven/130° C.).

Example 2

The Production of an Inventive Multicoat Color Paint System

To produce the multicoat system, steel test panels coated with anelectrocoat in a dry film thickness of from 18 to 22 μm were coated witha waterborne primer-surfacer. The resultant waterborne primer-surfacerfilm was baked at 160° C. for 20 minutes to give a primer-surfacer coatwith a dry film product thickness of from 35 to 40 μm. Theprimer-surfacer coat was subsequently coated with a black aqueousbasecoat material from BASF Coatings AG in a film thickness of from 12to 15 μm. The resultant aqueous basecoat films were flashed off at 80°C. for 10 minutes. Thereafter, the dual-cure clearcoat material fromexample 1 was applied pneumatically using a gravity-feed cup gun in onecross-pass in a film thickness of from 40 to 45 μm. Subsequently, theclearcoat films were flashed off at room temperature for 5 minutes andat 100° C. for 5 minutes, exposed to UV radiation (dose: 3,000 mJ/cm²),and then baked together with the aqueous basecoat films in a forced airoven at a panel temperature of 140° C. for 20 minutes.

For the wetting test, relatively thin clearcoat films were applied andbaked in the manner described above. The test revealed that very goodwetting was present even with a film thickness below 20 μm.

For the leveling test, the clearcoat material was electrostaticallyapplied vertically and horizontally to the test panels. This was doneusing an Eco-bell with direct charging. The leveling was assessedvisually as being particularly good (very smooth surface). This isunderscored by the measurement of the wave scan values, with which theskilled worker is familiar:

-   -   long wave/short wave at 40 um, horizontal application: 8.3/4    -   long wave/short wave at 40 μm, vertical application: 12.1/5.2        (instrument: Byk/Gardner—Wave scan plus).

In order to test for the tendency to run, customary and known perforatedmetal sheets with diagonal rows of holes were used instead of the testpanels. The clearcoat material was applied electrostatically in a filmthickness of <20 μm to 65 μm. This was done using an Eco-bell withdirect charging. Basecoat and clearcoat were baked in the verticalposition. Initial signs of runs occurred only at clearcoatthicknesses >50 μm; the runs reached a length of 1 cm only at 52 μm.

The resultant multicoat paint system was highly brilliant and had agloss (20°) to DIN 67530 of 90.

The scratch resistance was determined with the aid of the sand test (cf.German patent application DE 198 39 453 A 1, page 9 lines 1 to 63) usingthe metal test panels described above. Following damage a loss of glossby only 11.5 units (20°) to 79.5 was found, which underlined the highscratch resistance. The gloss rose after two hours at 40° C. to 80.2 andafter two hours at 60° C. to 81.6, which demonstrated the very goodreflow characteristics.

Furthermore, the scratch resistance was assessed with the aid of thebrush test (cf. the German patent application DE 198 39 453 A 1, page 9lines 17 to 63) using the metal test panels described above. Followingdamage, a loss of gloss by only 4.8 units (200) to 85.2 was found, whichunderlined the high scratch resistance. The gloss rose after two hoursat 40° C. to 85.9 and after two hours at 60° C. to 86.5, whichunderlined the very good reflow characteristics.

The chemical resistance was determined in accordance with BART.

The BART (BASF ACID RESISTANCE TEST) was used to determine theresistance of film surfaces to acids, alkalis and water drops. Afterbaking, the coating was exposed to further temperature loads in agradient oven (30 min at 40° C., 50° C., 60° C. and 70° C.). Beforehand,the test substances (1%, 10% and 36% strength sulfuric acid; 5%sulfurous acid, 10% hydrochloric acid, 5% sodium hydroxide solution, DI(i.e., deionized) water (1, 2, 3 or 4 drops)) were applied in a definedmanner using a volumetric pipette. Following exposure to the substances,they were removed under running water and the damage was assessedvisually after 24 h in accordance with a specified scale:

Rating Appearance 0 no defect 1 slight marking 2 marking/matting/nosoftening 3 marking/matting/color change/softening 4 cracks/incipientetching 5 clearcoat removed

Each individual mark (spot) was evaluated and the result was noted foreach coating in an appropriate form (e.g., rating totals for onetemperature).

The results of the tests are given in the table.

The BART underlines the extraordinary acid resistance of the multicoatpaint system of the invention and of the clearcoat of the invention.

TABLE The BART acid resistance of the inventive multicoat paint systemTest substance 40° C. 50° C. 60° C. 70° C. 1% sulfuric acid 0 0 0 1 10%sulfuric acid 0 0 0 2 36% sulfuric acid 0 0 0.5 3 10% hydrochloric 0 0 00 acid 5% sulfurous acid 0 0 0 1 5% sodium hydroxide 0 0 0 0 solution DIwater 1 0 0 0 0 DI water 2 0 0 0 0 DI water 3 0 0 0 0 DI water 4 0 0 0 0Total 0 0 0.5 7

1. A dual-cure mixture curable thermally and with actinic radiation andcontaining carbamate and/or allophanate groups, comprising (A) at leastone constituent selected from the group consisting of (A1) at least oneof a compound, an oligomer and a polymer, wherein the compound, theoligomer, and the polymer each contain at least one allophanate group,at least one carbamate group, or at least one carbamate group and atleast one allophanate group, and (A2) at least one of a compound, anoligomer and a polymer, wherein the compound, the oligomer, and thepolymer each contain at least one allophanate group, at least onecarbamate group, and at least one carbamate group and at least oneallophanate group, and each additionally contain at least oneallophanate-reactive functional group, at least one carbamate-reactivefunctional group, or at least one carbamate-reactive functional groupand at least one allophanate-reactive functional group, which aresubstantially or entirely free from reactive functional groups thatcontain at least one bond that can be activated with actinic radiation,(C) at least one constituent containing on average per molecule at leastone reactive functional group having at least one bond that can beactivated with actinic radiation; with the proviso that if there are noconstituents (A2), the dual-cure mixture further comprises (B) at leastone constituent selected from the group consisting of at least onecompound, at least one oligomer and at least one polymer wherein thecompound, the oligomer, and the polymer each contain at least oneallophanate-reactive functional group, at least one carbamate-reactivefunctional group, or at least one carbamate-reactive functional groupand at least one allophanate-reactive functional group, and (D)optionally, at least one rheological aid.
 2. The dual-cure mixture ofclaim 1, wherein the allophanate-reactive functional group and thecarbamate-reactive functional group are each selected from the groupconsisting of N-methylol groups and N-methylol ether groups.
 3. Thedual-cure mixture of claim 1, wherein the bonds that can be activatedwith actinic radiation are selected from the group consisting ofcarbon-hydrogen single bonds, carbon-carbon single bonds, carbon-oxygensingle bonds, carbon-nitrogen single bonds, carbon-phosphorus singlebonds, carbon-silicon single bonds, carbon-carbon double bonds,carbon-oxygen double bonds, carbon-nitrogen double bonds,carbon-phosphorus double bonds, and carbon-silicon double bonds.
 4. Thedual-cure mixture as claimed in claim 3, wherein the bonds that can beactivated with actinic radiation are present in at least one of a(meth)acrylate group, an ethacrylate group, a crotonate group, acinnamate group, a vinyl ether group, a vinyl ester group, anethenylarylene group, a dicyclopentadienyl group, a norbornenyl group,an isoprenyl group, a isopropenyl group, an allyl group, a butenylgroup, an ethenylarylene ether group, a dicyclopentadienyl ether group,a norbornenyl ether group, an isoprenyl ether group, a isopropenyl ethergroup, an allyl ether group, a butenyl ether group, an ethenylaryleneester group, a dicyclopentadienyl ester group, a norbornenyl estergroup, an isoprenyl ester group, an isopropenyl ester group, an allylester group, and a butenyl ester group.
 5. The dual-cure mixture ofclaim 4, wherein the bonds that can be activated with actinic radiationare present in a (meth)acrylate group.
 6. The dual-cure mixture of claim1, wherein the oligomers and the polymers are each at least one of anaddition (co)polymer of at least one ethylenically unsaturated monomer,a polyaddition resin and a polycondensation resin, wherein the addition(co)polymer is at least one of a random (co)polymer, an alternating(co)polymer, and a block (co)polymer, and wherein the addition(co)polymer is at least one of linear, branched, and comb.
 7. Thedual-cure mixture of claim 6, wherein the addition (co)polymer isselected from the group consisting of (meth)acrylate copolymers andpolyvinyl esters, and the polyaddition resin and the polycondensationresin are each selected from the group consisting of polyesters, alkyds,polyurethanes, polylactones, polycarbonates, polyethers, epoxyresin-amine adducts, polyureas, polyamides and polyimides.
 8. Thedual-cure mixture of claim 1, wherein the constituent (B) is selectedfrom the group consisting of amino resins.
 9. The dual-cure mixture ofclaim 1, wherein the constituents (C) is selected from the groupconsisting of reactive diluents curable with actinic radiation,(meth)acryloyl-functional (meth)acrylic copolymers, polyether(meth)acrylates, polyester (meth)acrylates, unsaturated polyesters,epoxy (meth)acrylates, urethane (meth)acrylates, amino (meth)acrylates,melamine (meth)acrylates, silicone (meth)acrylates, and combinationsthereof.
 10. The dual-cure mixture of claim 9, wherein the constituents(C) is selected from the group consisting of pentaerythritol triacrylateand dipentaerythritol pentaacrylate.
 11. The dual-cure mixture of claim1, further comprising the at least one rheological aid selected from thegroup consisting of silicas and urea derivatives, wherein the ureaderivatives are prepared by reacting A) at least one of i) at least oneamine and ii) water with at least one isocyanate in the presence of B)at least one of i) at least one constituent selected from the groupconsisting of (a) at least one of an oligomer and a polymer, wherein theoligomer and the polymer each contain at least one allophanate group, atleast one carbamate group, or at least one carbamate group and at leastone allophanate group, and (b) at least one of an oligomer and apolymer, wherein the oligomer and the polymer each contain at least oneallophanate group, at least one carbamate group, and at least onecarbamate group and at least one allophanate group, and eachadditionally contain at least one allophanate-reactive functional group,at least one carbamate-reactive functional group, or at least onecarbamate-reactive functional group and at least oneallophanate-reactive functional group, which are substantially orentirely free from reactive functional groups that contain at least onebond that can be activated with actinic radiation, and ii) at least oneamino resin.
 12. The dual-cure mixture of claim 1, further comprising atleast one wetting agent.
 13. The dual-cure mixture of claim 12, whereinthe at least one wetting agent is selected from the group consisting ofsiloxanes, fluorine compounds, carboxylic monoesters, phosphates,polyacrylic acids, copolymers of polycarboxylic acids, andpolyurethanes.
 14. The dual-cure mixture of claim 1, further comprisingat least one pigment selected from the group consisting of organicpigments, inorganic pigments, color and/or effect pigments, electricallyconductive pigments, magnetically shielding pigments, fluorescentpigments, organic fillers, inorganic fillers, and nanoparticles, whereinthe pigment is different from the at least one rheological aid.
 15. Thedual-cure mixture of claim 1, further comprising at least onephotoinitiator.
 16. A process for preparing the dual-cure mixture ofclaim 1 comprising mixing the constituents, wherein if the rheologicalaid is included, the rheological aid is prepared by a process comprisingreacting A) at least one of i) at least one amine and ii) water with atleast one isocyanate in the presence of B) at least one of i) at leastone constituent selected from the group consisting of (a) at least oneof an oligomer and a polymer, wherein the oligomer and the polymer eachcontain at least one allophanate group, at least one carbamate group, orat least one carbamate group and at least one allophanate group, and (b)at least one of an oligomer and a polymer, wherein the oligomer and thepolymer each contain at least one allophanate group, at least onecarbamate group, and at least one carbamate group and at least oneallophanate group, and each additionally contain at least oneallophanate-reactive functional group, at least one carbamate-reactivefunctional group, or at least one carbamate-reactive functional groupand at least one allophanate-reactive functional group, which aresubstantially or entirely free from reactive functional groups thatcontain at least one bond that can be activated with actinic radiation,and ii) at least one amino resin.
 17. The dual-cure mixture of claim 1wherein the dual-cure mixture is one of a coating material, an adhesiveor a sealing compound.
 18. The dual-cure mixture of claim 17, whereinthe coating material is a clearcoat material.
 19. A method comprisingapplying the dual-cure mixture of claim 17 to one of a motor vehiclebody, a motor vehicle part, a building, furniture, a window, a door, apart, a coil, a container, a package, an electrical component, or awhite good.